*{
    margin: 0;
    padding: 0;
}
header{
    width: 1378px;
    height:auto;
    background: #ff0;
    position:relative;
    top: 0;
    left: 50%;
    margin-left: -689px;
}

nav{
    width: 1378px;
    height: auto;
    background: #f00;
    position: relative;
    top: 0;
    left: 50%;
    margin-left: -689px;
}
div.banner{
    width: 1378px;
    height: auto;
    background: #00f;
    position: relative;
    top: 0;
    left: 50%;
    margin-left: -689px;
}
section{
    width: 1378px;
    height: auto;
    background: #bfa;
    position: relative;
    top: 0;
    left: 50%;
    margin-left: -689px;
}
footer{
    width: 1378px;
    height: auto;
    background: #0f0;
    position: relative;
    top: 0;
    left: 50%;
    margin-left: -689px;
}